Scientific merits and analytical challenges of tree-ring densitometry
MetadataShow full item record
X-ray microdensitometry on annually-resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density parameter (MXD), but also increasingly through other density parameters. For fifty years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resolution. Here we review the current understanding and merits of wood density for tree-ring research, associated microdensitometric techniques, and analytical measurement challenges. The review is further complemented with a careful comparison of new measurements derived at 17 laboratories, using several different techniques. The new experiment allowed us to corroborate and refresh ?long-standing wisdom?, but also provide new insights. Key outcomes include; i) a demonstration of the need for mass/volume based re-calibration to accurately estimate average ring density; ii) a substantiation of systematic differences in MXD measurements that cautions for great care when combining density datasets for climate reconstructions; and iii) insights into the relevance of analytical measurement resolution in signals derived from tree-ring density data. Finally, we provide recommendations expected to facilitate future inter-comparability and interpretations for global change research.
Björklund , J , von Arx , G , Nievergelt , D , Wilson , R , Van den Bulcke , J , Günther , B , Loader , N J , Rydval , M , Fonti , P , Scharnweber , T , Andreu-Hayles , L , Büntgen , U , D'Arrigo , R , Davi , N , De Mil , T , Esper , J , Gärtner , H , Geary , J , Gunnarson , B E , Hartl , C , Hevia , A , Song , H , Janecka , K , Kaczka , R J , Kirdyanov , A V , Kochbeck , M , Liu , Y , Meko , M , Mundo , I , Nicolussi , K , Oelkers , R , Pichler , T , Sánchez-Salguero , R , Schneider , L , Schweingruber , F , Timonen , M , Trouet , V , Van Acker , J , Verstege , A , Villalba , R , Wilmking , M & Frank , D 2019 , ' Scientific merits and analytical challenges of tree-ring densitometry ' , Reviews of Geophysics , vol. Early View . https://doi.org/10.1029/2019RG000642
Reviews of Geophysics
Copyright © 2019. American Geophysical Union. All Rights Reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.1029/2019RG000642
DescriptionR.W. was supported by NERC grant NE/K003097/1.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.